Continuing a long-standing goal from this P01 to explicate important links between speech and reading, in this new proposal we propose a brain-based account of atypical reading development that traces phonological (and later reading deficits) to earlier problems in the machinery for speech perception, production, and perception/production interactions. To test this account, we focus on 1) how sensorimotor systems associated with speech perception and production support the development of age-appropriate phonological and later orthographic learning; 2) how becoming print-literate feeds back upon and modifies speech perception and production; and 3) how these relationships differ in contrastive orthographies. We employ a hybrid longitudinal/cross sectional design to examine concurrent and prospective brain-behavior relationships in high and low risk children as they transition from basic speech processing to phonological awareness (ages 4 to 6.5) and orthographic learning (ages 6 to 8.5). At the cognitive level of analysis we employ experiments that examine quality of speech perception and speech production, and sensorimotor adaptation, along with more conventional assessments of phonological processing, language, cognitive and sensorimotor skills. At the neurobiological level of analysis we utilize age-appropriate multimodal neuroimaging (including Near Infrared Spectroscopy (NIRS), EEG, and structural and functional MRI), to explicate concurrent and prospective brain behavior relationships associated with typical and atypical reading outcomes. In this older age range (6 to 8.5) we will also examine two contrastive orthographies (Spanish and Chinese) to test whether hypothesized bidirectional relationships between speech and reading development are language invariant or language specific at both the neurobiological and cognitive levels of analysis. RELEVANCE (See instructions): This program is relevant to the understanding the development of spoken and written language competence which is crucial for successful academic and life outcomes. Project I, by exploring the neurocognitive origins of atypical reading , adds a critical developmental perpsective on speech and reading relations in the Program, and is highly relevant to issue of improved early detection of reading disability.